Originally Posted by Technic
"Scratching" noise is caused by loose connection somewhere in the amp (inputs/outputs). Hiss is the noise floor of the amp just amplified over an acceptable level.
Some batch of PDX amps used to produce hiss at minimum gain/no audio. My personal solution for that was to replace that particular PDX amp. Problem solved.
Bad connection at the harness RCA will produce a different kind of noise, "scratching", pops, low volume level or simply no sound at that particular RCA/speaker output.
Tried all still same!! Checked The RCA cables all cable is sutring where they should be, still scarathing noice and hissing and sub passenger side blaffering like flop floooop